Idea 9of 22Builds onParts stacked in one bar
Read a middle piece
How do you read a piece that does not start at 0?
Today you'll discover
- where a middle piece starts and ends
- why its top is not its count
- how to subtract to find it
Think firstRoom 14's bus piece, ringed
How many Room 14 students ride the bus?
Decide first, then press Next. Find both edges of the ringed piece.
Room 12 and Room 14's stacked bars on a count scale, Room 14's bus piece ringed. Marks beside each bar give where each piece ends: Room 14's at 9, 15, 20 and 25. Then the counts inside the pieces. The last step rings Grade 4's soccer piece, which runs from 10 to 16.
See the whole ideathe big idea and the key word, in one place
The big idea
A piece's count is its top edge minus its bottom edge: 15 − 9 = 6.
Room 14Walk 0 to 9: 9. Bus 9 to 15: 6. Car 15 to 20: 5. Bike 20 to 25: 5.
Easy to get wrongReading the top of a middle piece gives a running total, not that piece. 15 is walkers plus bus riders.
Key word
- edge
- where a piece of a stacked bar starts or ends, read on the scale
Ready to use it?
- Read a middle piece of a stacked bar.
- Check that the pieces add to the whole bar.